This disclosure relates to novel aqueous ink-jet inks having improved salt stability containing an aqueous vehicle, a colorant, and a mixture of a water-borne anionic polymeric binder and a water-borne non-ionic polymeric binder.
Ink-jet digital printing method is becoming increasingly important for the printing of textiles. It offers a number of potential benefits over conventional printing methods such as screen printing. Digital printing eliminates the set-up expense associated with screen preparation and can potentially enable cost-effective short run production. Digital printing furthermore allows visual effects, such as tonal gradients and repeat of printed patterns that cannot be practically achieved with a screen printing process. Especially beneficial is the ease in changing the patterns of originals during production of digital printing, when it is possible to respond to a change in patterns or other requirements within a short period of time.
U.S. Patent Application Publication No. 20070060670 discloses an aqueous white ink containing polyurethane binder for printing onto textile substrates. The textile substrates are pretreated with an inorganic salt solution. While pretreatment of the textile substrate with an inorganic salt solution can precipitate the white ink to prevent it from penetrating into the fabric, the inorganic salt solution can also interact with color inks causing them to precipitate and consequently compromise the printed color image. A need exists for highly stable ink-jet inks that can be printed on various substrates to form durable, high quality image. The present disclosure satisfies this need by providing an ink containing a mixture of a water-borne anionic polymeric binder and a water-borne non-ionic polymeric binder. The presence of an non-ionic polymeric binder in an ink reduces the interaction of the ink with salt(s) that are present in the print substrate, and consequently improves the quality of printed images.